1. Field of the Invention:
The invention relates to a rotary tampon printing machine for printing large-area objects such as automobile glazings, with a block that keeps the printing ink in the desired design and a tampon roller made of a cylindrical roller body that transfers the printing ink from the block to the object and a tampon placed on the surface area of the cylindrical roller body.
2. Description of the Related Art:
In known rotary tampon printing machines, the tampon placed on the roller body of the tampon roller has the form of a hollow cylinder with a continuously even wall thickness. The block, for its part, is also made as a roller in the known rotary tampon printing machines, and the ink transfer to the block roller occurs in that the block roller takes up the printing ink by dipping into a container containing the printing ink, and the excess printing ink above the container is wiped off by a wiper lying against the roller surface.
A condition for satisfactory printing is that the contact pressure of the tampon roller along the contact line or along the striated contact surface with the object to be printed is evenly high and exhibits a certain minimum amount. The larger the surface to be printed, the more difficult it is to achieve an evenly high contact pressure.
A relatively large surface is exhibited, for example, by automobile glazings, in particular windshields or rear windows. But automobile glazings are increasingly being printed along the sheet edge on one side with a decorative border. Up to now, the imprinting of the decorative border has been performed exclusively using the screen printing process.
Imprinting a decorative border on automobile glazings using the screen printing process is, for its part, subject to specific drawbacks. Therefore, performing the inking right up to the edge of the glass sheets in the screen printing process, which is nevertheless desired for certain reasons, is in practice connected with great difficulties. Using the screen printing process, it is even completely impossible to apply the printing ink around the edge of the glass sheet. But that can also be suitable and desirable in certain cases.